Common variable immunodeficiency (CVID) comprises a heterogeneous group of primary immunodeficiency disorders. Immunophenotyping of memory B cells at the time of diagnosis is increasingly used for the classification of patients into subgroups with different clinical prognoses. The EUROclass classification is a widely used method. Levels of somatic hypermutation (SHM) have proven useful as a prognostic marker for recurrent respiratory tract infections. As time of presentation and diagnosis is highly variable in CVID patients, and diagnostic delay is a common problem, it is important to know whether classification parameters are stable over time. The purpose of the study was to address this question in a cohort of 33 CVID patients followed from 3 to 19 years after diagnosis (average follow-up 8.8 years).